EHarmony is a dating site which uses scientific methods of calculating the compatibility of users in order to find a perfect match for each of them. Each user fills in a detailed questionnaire about his or her lifestyle, opinions, beliefs and requirements for a future partner, and the system will try to find an appropriate person. There are 29 Dimensions of Compatibility grouped into Core Traits (e.g. Emotional Temperament, Social Style) and Vital Attributes (Beliefs, Experiences). The site's success rate is high (it claims more than 200 marriages between users a day!). The system offers assistance and 'Guided Communication' option, which helps new users break the ice. There are also many articles written by specialists, which contain tips and advice about dating and relationships, a success stories section, for those who found their match through eHarmony. The basic membership, including the personality test worth $40, is free, but a more advanced membership, which allows to communicate with other users, costs $59,95. Users must be legally single (not in separation), and can't have a history of more than 2 divorces. EHarmony provides the matchmaking service onlu for people of straight sexual orientation.